Nightcrawler

This immense worm is covered with plates of dead-black, chitinous armor. Its toothy maw yawns like a cave.
 

Nightcrawler (CR 18)

Gargantuan Undead (Extraplanar, Nightshade)
Alignment: Chaotic Evil
Initiative: +4
Senses: darksense, Darkvision 120 feet, Detect Magic, Low-Light Vision, Tremorsense 120 feet; Perception +33
Aura: desecrating aura (30 feet)
  Speed: 30 feet, Burrow 60 feet
Space: 20 feet
 

Defense

Armor Class: 33, touch 6, flat-footed 33 (+27 natural, -4 size)
Hit Points: 312 (25d8+200)
Saving Throws: Fort +16, Ref +10, Will +23
Damage Reduction: 15/good and silver
Immunity: cold, undead traits
Spell Resistance: 29
Weaknesses: light aversion
 

Offense

Melee: bite +32 (4d10+18/19-20 plus 4d6 cold and Grab), sting +32 (4d6+18/19-20 plus 4d6 cold and poison)
Reach: 20 feet
  Special Attacks: channel negative energy (9d6, DC 31, 9/day), Energy Drain (1 level, DC 28), Swallow Whole (4d10+22 bludgeoning plus Energy Drain, AC 23, 31 hp)
  Spell-Like Abilities (CL 18th; Concentration +24):

Statistics

StrDexConIntWisCha
41 (+15) 10 (+0) - 20 (+5) 21 (+5) 23 (+6)
Base Attack Bonus: +18
CMB +37 (+41 Grapple)
CMD 47 (can't be tripped)
  Feats: Command Undead, Critical Focus, Greater Vital Strike, Improved Critical (bite), Improved Critical (sting), Improved Initiative, Improved Vital Strike, Iron Will, Quicken Spell-Like Ability (Cone of Cold), Staggering Critical, Vital Strike
  Skills: Intimidate +34, Knowledge (arcana) +33, Knowledge (planes) +30, Knowledge (religion) +33, Perception +33, Sense Motive +33, Spellcraft +33, Stealth +16 (+24 in darkness), Swim +40
  • Racial Modifiers: +8 Stealth in dim light and darkness
Languages: Abyssal, Common, Infernal; telepathy 100 ft.
 

Special Abilities

Energy Drain (Su)

A creature that has been swallowed whole by a nightcrawler gains 1 negative level each round.

Poison (Su)

Sting-injury; save Fort DC 28; frequency 1/round for 6 rounds; effect 1d4 Constitution drain and 1 negative level; cure 3 consecutive saves. The save DC is Charisma-based.
 

Ecology

Environment: Any, Plane of Death
Organization: solitary or pair
Treasure: standard

  Although the nightcrawler might appear to be little more than an immense and frightening vermin, with its centipede-like body and numerous glowing eyes, it is actually incredibly intelligent. When not cleansing the deep caverns of life, the nightcrawler spends its time plotting how best to carry out its own private stages of the overall nightshade plan to expunge life from all worlds, conferring with its undead minions and, when necessary, observing living creatures from afar while invisible to learn about hidden enclaves that its depredations might otherwise have missed.
  It would be one thing if the nightcrawlers remained in the deep caverns, for these regions are rife with foul life the world is better off without. Yet unfortunately for those who dwell upon the surface, nightcrawlers often crawl up through the tunnels to bring their devastation to the night above. Although they always retreat underground before the first tentative rays of dawn color the eastern skies, they can spread an incredible amount of ruin in the span of a few short hours each night.
  A nightcrawler is 60 feet long and weighs 10,000 pounds.